This disclosure relates to a robot assembly, particularly with a painting robot, and a corresponding assembly method for such a robot assembly.
In modern coating plants for painting vehicle body components, multi-axis painting robots with serial kinematics are usually used in order to guide rotary atomizers with maximum freedom of movement. In this arrangement, the rotary atomizer is generally located on an assembly flange on a robot wrist axis of the painting robot, the rotary atomizer being provided, via the assembly flange, with the required media. Exemplary media include, for example, drive air to drive a compressed air turbine, shaping air for shaping the spray jet, high voltage for electrostatic coating charge, bearing air for air bearings in the rotary atomizer, solvent lines and return lines.
In such coating plants, it is necessary, for example in test phases, to sequentially test different types of application devices (e.g. rotary atomizers, air atomizers, etc.), which requires the assembled application devices to be replaced.
A known method for replacing the application devices exists in that the individual supply lines for the application device are released at the next separating point behind the assembly flange in order to enable another application device to be assembled. However, this method for replacing an application device is extremely time-intensive as the supply lines have to be individually separated and reconnected to each other. In addition, the separating points for the individual supply lines cannot normally be placed immediately behind the wrist axis, as a rotation angle of approximately ±540° has to be compensated for. Thus, the separating point of the supply lines is usually disposed relatively far upstream in the robot arm, which makes it difficult to separate and reconnect the individual supply lines. This known method for replacing an application device on a painting robot is therefore extremely complicated and may require up to two hours to change over to another atomizer type.
Another known method for replacing an application device on a painting robot is described below with reference to FIGS. 8A-8D. The figures show an electrostatic atomizer 1 with a rotary bell 2 and an external charge ring 3 for electrostatically charging the coating agent, which is known per se in the prior art. The atomizer 1 is assembled via an intermediate flange 4 on a robot wrist axis 5, said robot wrist axis 5 being part of a conventional multi-axis painting robot with serial kinematics, so that a detailed description of the painting robot can be dispensed with at this point. The intermediate flange 4 has a flange face 6 on the robot-side, which is linked to a corresponding robot flange 7 on the robot wrist axis 5. In addition, the intermediate flange 4 has an atomizer-side flange face 8, which is connected to a corresponding atomizer flange 9 of the rotary atomizer 1. In this arrangement, the rotor flange 7 on the robot wrist axis 5 provides not only the supply lines (e.g. for drive air, shaping air, high voltage, paint, solvent, return, etc.) for the currently assembled type of rotary atomizer 1. The robot flange 7 also has a connection configuration with a multiplicity of connections for all possible types of application devices on the robot wrist axis 5. In this arrangement, the intermediate flange 4 is individually matched to the corresponding type of rotary atomizer 1 and selects from those connections that are provided on the robot flange 7 the connections that are required by the corresponding type of rotary atomizer 1. The connections required by the corresponding type of rotary atomizer 1 are then provided in the required connection configuration on the atomizer-side flange face 8 of the intermediate flange 4 so that the atomizer 1 can be assembled on the intermediate flange 4. The intermediate flange 4 is thus an adapter, which matches the required connection configuration to the corresponding type of rotary atomizer 1.
In this arrangement, the intermediate flange 4 has a specific construction length LF, which, with a corresponding construction length LZ of the rotary atomizer 1, adds up to an overall construction length LG between the robot flange 7 and a tool centercenter point TCP. In this arrangement, the painting robot is actuated by a central robot control, the overall construction length LG between the robot flange 7 and the tool centercenter point TCP being stored in the robot control. The problem here is that replacing the rotary atomizer 1 together with the individually matched intermediate flange 4 normally leads to a change in the actual construction length LG between the robot flange 7 and the tool center point TCP. Firstly, this is due to the fact that the newly replaced atomizer 1 can usually have a different construction length LZ. Secondly, however, the change in the overall construction length LG when replacing the rotary atomizer 1 is also due to the fact that the intermediate flange 4 can have a different construction length LF. After replacing the rotary atomizer 1 with the intermediate flange 4, however, the changed construction length LG results in the construction length LG stored in the robot control no longer matching the actual construction length LG so that the tool center point TCP is actuated along an incorrect track. This in turn means that the coating results obtained in this way are practically incomparable.
A replacement flange is known from DE 90 01 451 U1, which enables a real application device to be replaced by a simulation tool. In this arrangement, the replacement flange accomplishes a geometric adjustment so that, in its spatial arrangement in the robot, the simulation tool matches the real application device. However, this concept has so far not been suited to replacing real application devices as such a replacement flange requires a multiplicity of line ducts, which cannot be accommodated in the available space.
Furthermore, WO 2010/028864 A2, EP 1 285 733 A2 and DE 37 80 874 T2 are also prior art.
Therefore, it would be desirable to replace the application device on an application robot simply and quickly, where the coating results obtained with different types of application devices may also be comparable with each other.